document.getElementsByClassName = function(class_name) {
    var docList = this.all || this.getElementsByTagName('*');
    var matchArray = new Array();

    /*Create a regular expression object for class*/
    var re = new RegExp("(?:^|\\s)"+class_name+"(?:\\s|$)");
    for (var i = 0; i < docList.length; i++) {
        if (re.test(docList[i].className) ) {
            matchArray[matchArray.length] = docList[i];
        }
    }

	return matchArray;
}//eof annonymous function

var counter = 0;

var img = document.getElementById("img_box");
var image = null;

// Bilderwechsel
function showimage(i)
{
hide(img);	
image = new Image();
image.onload=fadeIt;
image.src = i;   
}

function fadeIt(){
	fade(0,img,counter);
	}

function fade(step,layer,count) {
	
if(counter==count){
		

	if(image != null) eval("document['picture'].src = image.src");
	
	if(step==0){
		
		counter++;
		count++;
		
		layer.style.opacity = 0;
		layer.style.filter = "alpha(opacity=" + 0 + ")"; // IE
		}

            step = step || 0;

            layer.style.opacity = step/100;
            layer.style.filter = "alpha(opacity=" + step + ")"; // IE

            step = step + 2;

            if (step <= 100) {
                window.setTimeout(function () { fade(step,layer,count); }, 1);
            }
}
}

function hide(layer) {

            layer.style.opacity = 0;
            layer.style.filter = "alpha(opacity=0)"; // IE

}

// Tabwechsel

var tab_index=1;

function showtabnext(){
	showtab(tab_index+1);
}
function showtabback(){
	showtab(tab_index-1);
}

function showtab(t) 
{ 
var tabname = "tab_"+t;
var tab = document.getElementById(tabname);

if(tab!=null){
	tab_index = t;
	
	var tabs = document.getElementsByClassName(tab.className);
	var tab_link = document.getElementById(tabname+"_link");
	var tab_links = document.getElementsByClassName("tab_current");
	
	for(i=0; i<tabs.length; i++) 
			tabs[i].style.display = 'none';
			
	for(i=0; i<tab_links.length; i++){
			tab_links[i].className='';
	}
	
	tab_link.className='tab_current';
	tab.style.display='block';
	
	fade(0,tab, counter);
}
}